A subcritical or supercritical water is used to selectively etch a silicon nitride film against a silicon dioxide film or to selectively etch a silicon dioxide film against a crystalline silicon region. This method is applicable to a process of forming a MISFET or a charge emitting device.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An apparatus for etching a target layer of an object being processed using a fluid, the apparatus comprising: a vessel in which the object being processed is loaded and subjected to an etching process, and which has a closed system and pressure therein that can be increased higher than the atmospheric pressure; a fluid supplier for pressurizing the fluid and supplying the fluid into the vessel; means for separating the fluid, drained from the vessel, from a substance resulting from the etching process; a reservoir for storing the fluid that has been separated by the separating means; means for circulating the fluid from the reservoir back to the fluid supplier; and a pressure controlling mechanism for controlling the pressure in the vessel.
2. The apparatus of claim 1 , wherein the fluid is a water, and wherein the separating means vaporizes the water to separate the water from the substance resulting from the etching process.
3. The apparatus of claim 1 , wherein the separating means condenses the substance resulting from the etching process to separate the substance from the fluid.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
July 17, 2001
January 7, 2003
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